He began to wonder about the garbage's source, and decided to try an experiment. He took a ball he had found in the lake, wrote his address on it, and dropped it into the storm sewer gutter in front of his home.

Foam toe separators, typically used during manicures and pedicures, pulled from the lake.Nikki Tundel for MPR News

After the next rainfall, he found the ball in the lake next to a storm sewer outfall, from which the trash that washes from urban streets into gutters makes it into the lake.

"Turns out that the area of drainage that empties into Lake Hiawatha is a huge area of urban streets that empties right into the lake without any mitigation whatsoever," he said.

Collecting the trash has become Connaughty's preoccupation. Since 2015, he and more than 60 volunteers have removed 4,500 pounds of trash from the lake.

And the trash has also made its way into Connaughty's art. A few years ago, he did an art exhibition of some of the objects he had found — about 10 percent of the 70 bags of trash he had collected at that point.

In the style of an archaeologist, Connaughty wrote a report inventorying the objects and discussing their use as though they were from a bygone culture.

The report is filled with musings on the purpose of some of the items collected, such as plastic toy soldiers and tanks: "There is evidence of conflict in numerous military representations. Armed with weaponry, miniaturized reproductions of the species engaged in armed conflict, with multiple representations of weapons and armored vehicles for military use."

Connaughty continues to organize clean-up efforts around the lake and hopes to change the way people think about water and our connection to it.

"It's easy to become misanthropic when you're picking up trash," he said. "But the one thing that's kept me going is that I'm confident we're going to come together as a community and resolve the problem."

This story is part of The Water Main from MPR News, helping Minnesotans understand the value of water in our lives. Check out @thewatermain on Twitter.

Gallery

Since 2015, Connaughty and a group of volunteers have removed 4,500 pounds of trash from the area.Nikki Tundel for MPR NewsView full galleryConnaughty collects and catalogs some of the items he finds along the shoreline, like these Nerf darts.Nikki Tundel for MPR NewsA selection of items from the lake.Nikki Tundel for MPR NewsSean Connaughty is working to clean up Lake Hiawatha in Minneapolis.Nikki Tundel for MPR NewsSean Connaughty is an artist, professor, and community activist.Nikki Tundel for MPR NewsBubble wands, pulled from the lake.Nikki Tundel for MPR NewsA doll's head from the lake.Nikki Tundel for MPR NewsValleyfair Snoopys found in the lake.Nikki Tundel for MPR NewsSean ConnaughtyNikki Tundel for MPR NewsConnaughty sorts through some of his finds.Nikki Tundel for MPR News